Ceiling modules with lamp housings

ABSTRACT

A ceiling module formed of four trapezoidal panels, each convergent edge of each of the panels being contiguous a convergent edge of another panel, the long bases of the panels lying in a common plane and the short bases of the panels defining an open seat. The panels and an electric light source are supported by a framework consisting of four sheet metal beams secured together face to face. Each of the beams includes an outwardly turned spine part extending from a corner of the open seat to an outside corner of the module, a lamp housing part extending along a side of the open seat and an attachment part extending outwardly along a line of contiguity between adjacent panels and secured to the spine part of an adjacent beam. A cover is mounted on the upper edges of the lamp housing. A lighting panel is mounted in the open seat by four parallel spring-loaded pins at the corners of the lighting panel. A lighting source is mounted in the lamp housing above the lighting panel. A trim rail around the periphery of the module is provided with inwardly turned ears which are secured to the spine to stiffen the spines.

[ CEILING MODULES WITH-I L w HOUSINGS [75] Inventors: Thomas C. Halfaker, St. Louis; Leo G. Stahlhut, Kirkwood, both of Mo.

[73] Assignee: Emerson Electric Co., St. Louis County, Mo.

[22] Filed: Jan. 23, 1973 [21] Appl. No.: 326,061

[52] 10.5. CI. 240/9 R, 52/28, 240/51.11 R, 240/73 BC [51] Int. Cl. F21v 21/02, E04b 5/52 [58] Field of Search 240/9 R, 9 A, 52, 73 R, 240/73 BC, 51.11 R, 78 H; 52/28; 98/40 DL [56] References Cited UNITED STATES PATENTS 3,343,309 9/1967 Netz et al. 3,343,310 9/1967 Netz et al. 3,372,270 3/1968 Quin et al. 3,426,188 2/1969 Bavanowski 3,512,313 5/1970 Harz 3,581,448 6/1971 Roux 3,743,826 7/1973 Halfaker ..'98/40 DL OTHER PUBLICATIONS New G-P Headquarters: Fresh Technologies Create a Loudmark, Building Design & Construction, June 1970, pp. 58-66 & accompanying blueprint.

[451 Aug. 20, 1974 SCT A ceiling module formed of four trapezoidal panels,

each convergent edge of each of the panels being contiguous a convergent edge of another panel, the long bases of the panels lying in a common plane and the short bases of the panels defining an open seat. The panels and an electric light source are supported by a framework consisting of four sheet metal beams se cured together face to face. Each of the beams includes an outwardly turned spine part extending from a comer of the open seat to an outside comer of the module, a lamp housing part extending along a side of the open seat and an attachment part extending outwardly along a line of contiguity between adjacent panels and secured to the spine part of an adjacent beam. A cover is mounted on the upper edges of the lamp housing. A lighting panel is mounted in the open seat by four parallel spring-loaded pins at the comers of the lighting panel. A lighting source is mounted in the lamp housing above the lighting panel. A trim rail around the periphery of the module is provided with inwardly turned ears which are secured to the spine to stiffen the spines.

21 Claims, 16 Drawing Figures ages-1901s PATENTEDAUBZOISH FIG.I

PAIENTEDAUBZOIBM sum as S irj\ FEGH.

CEILING MODULES WITH LAMP HOUSINGS BACKGROUND OF THE INVENTION This invention relates to ceiling modules and in particular to a new ceiling module construction. The use of ceiling modules, as disclosed and described more fully in Quin and Garnett, US. Pat. No. 3,372,270 (Mar. 5, 1968) to provide fully engineered environmental control through a highly flexible ceiling system has revolutionized attitudes toward the function and nature of ceiling components. The use of ceiling modules (that is, ceiling components of substantial size in the range of about 16 square feet to about 36 square feet) as repeating ceiling components to provide not only a ceiling-defining area, but also lighting and other environmental control elements such as air distribution, sound control and spatial division elements has allowed an unparalleled freedom in providing truly effective and attractive environmental control. The use of ceiling modules has also simplified the effectuation of each type of environmental control, and has provided these elements in an easily installed package.

The illustrative embodiments of ceiling modules described in Quin et al., Pat. No. 3,372,270, derive much of their strength from the pyramidal arrangement of the four trapezoidal panels and from the strength of the panels themselves. Therefore, commercial modules built in accordance with the illustrative embodiments of the aforesaid Quin et al patent have been pyramidal in form. The embodiment shown in FIG. 7 of Quin et al has not proven commercially successful, and the commercial embodiments of the modules have had an effective depth which is somewhat greater than is required by an ordinary suspended ceiling. Further, the pyramidal shape has tended to limit the positioning of partitions anywhere except along the channel lines between adjacent modules.

Many of the drawbacks of the Quin et al embodiments of ceiling module have been overcome in the ceiling modules disclosed and claimed in co-pending application of Thomas C. l-Ialfaker, Ser. No. 88,952, filed Nov. 12, 1970, now US. Pat. No. 3,743,826 issued July 3, 1973. However, the air-handling provisions of these modules require careful design of the air distribution system and limit the flexibility of such airhandling systems. Furthermore, the supporting framework of these modules is limited to flat modules.

SUMMARY OF THE INVENTION One of the objects of this invention is to provide an improved ceiling module which may be either flat or pyramidal and which is extremely rigid.

Another object is to provide such a module having a frame which may be made of relatively light gauge metal and which may have ceiling-defining panels which are made of light gauge metal or of other materials.

Another object is to provide such a module which is easily and inexpensively assembled.

Other objects will become apparent to those skilled in the art in light of the following description and accompanying drawings.

In accordance with one aspect of this invention, it has been found that ceiling modules built in accordance with many of the structural principles of the aforesaid Quin et al patent can be made stronger, lighter, and

more inexpensively by making the spines 40 thereof and the side wall 61 of the lamp housing 60 thereof integral parts of a rigid framework made up of sheet metal beams secured to each other in face-to-face relation, rather than making the spines integral with the ceiling-defining panels as in the preferred embodiment of the aforesaid Quin et al patent or making the spines separate pieces secured to the panels along their lines of contiguity as in some commercial modules made in accordance with the Quin et al patent. Preferably, the framework includes four identical elongate broadfaced sheet metal beams, each being bent to form a central lamp housing part, a spine part at one end and an attachment part at the other end, each of the spine part and attachment part being bent outwardly from the lamp housing part to form an angle of with the lamp housing part. These four beams are arranged to form a square lamp housing defined by the broad faces of the lamp housing parts, with the attachment part of each beam secured in face-to-face relation with a spine part of a contiguous beam, to form four diagonally outwardly extending spines. Preferably, the beams are secured to each other by deforming the material of one of the beams through an opening in the contiguous beam. Also preferably, flanges on the edges of four trapezoidal panels are secured to each other and to the spine by a frictional fit between alternately offset fingers along the lower edges of the spines and by the deformation of the flange material through openings in the lapped fingers and panel flanges. As in the aforementioned Quin et al patent, the outer edge of the panels form a rectangle and the inner edges form a central open seat for a closure member such as a lighting panel. In the preferred embodiments, the central seat has vertical sides and the closure member mounted in the seat is supported by the framework.

In accordance with another aspect of this-invention, the four diagonally outwardly extending spines are stiffened by a peripheral trim rail made up of four pieces, each of which extends along one edge of the module and includes at its end bent ear parts which are secured to the spines in face-to-face relation.

BRIEF DESCRIPTION OF THE DRAWINGS In the drawings, FIG. 1 is a top plan view of one illustrative embodiment of ceiling module of this invention, showing one embodiment of supporting framework of the invention;

FIG. 2 is a top plan view of one of the sheet metal framework beams of the module of FIG. 1;

FIG. 3 is a view in side elevation, as indicated at 3-3 of FIG. 2, of a portion of the beam of FIG. 2;

FIG. 4 is view in side elevation, as indicated at 4-4 of FIG. 2, of a part of the beam of FIG. 2;

FIG. 5 is a view in end elevation, as indicated at 5-5 of FIG. 3, of the free end of the beam of FIGS. 2-4;

FIG. 6 is a sectional view taken along the line 6-6 of FIG. 3;

FIG. 7 is a sectional view taken along the line 7-7 of FIG. 4;

FIG. 8 is a fragmentary sectional view of a lance part of the beam, taken along the line 8-8 of FIG. 4;

FIG. 9 is a fragmentary view in side elevation, as indicated at 9-9 of FIG. 1, of a trim rail of this invention;

FIG. 10 is a fragmentary top plan view, as indicated at 10 on FIG. 1, of the trim rail of FIG. 9;

FIG. 11 is a fragmentary view of the other end of the trim rail of FIGS. 9-10, as indicated at 1111 of FIG.

FIG. 12 is a fragmentary top plan view, as indicated at 12 on FIG. 1, of the end of the trim rail shown in FIG. 11;

FIG. 13 is a view in end elevation, as indicated at 13-13 of FIG. 12, of the end of the trim rail shown in FIGS. 11-12;

FIG. 14 is a sectional view of the assembled module taken along the line 14-44 of FIG. 1;

FIG. 15 is a sectional view taken along the line 15-15 of FIG. 1; and

FIG. 16 is a somewhat diagrammatic sectional view, corresponding generally to FIG. 14, of another embodiment of ceiling module of this invention, utilizing a light source different from that of FIG. 14.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring now to the drawings, and in particular to FIGS. 1-15, reference numeral 1 indicates one illustrative embodiment of ceiling module of this invention. As shown in FIG. 1, the module 1 includes a framework consisting of four identical sheet metal beams 3 (shown in detail in FIGS. 28), four identical trapezoidal panels 5, four identical trim rails 7 (shown in detail in FIGS. 9-13) and a cover plate 9. All of these pieces may be formed of relatively light sheet steel, for example 20 gauge cold rolled steel for the beams and trim rails and 22 gauge cold rolled steel for the panels and cover plate.

The modules of this invention may be assembled into ceilings in the same manner as those disclosed in Quin et al, Pat. No. 3,372,270, to produce ceilings which look like either the left side or the right side of FIG. 1 of the Quin et al patent. The preferred embodiment of module of this invention is flat, as shown at the left of Quin et al FIG. 1, but in other embodiments (such as that shown in FIG. 16) it may be pyramidal, as shown at the right of Quin et al FIG. 1. The assembly of the module 1, as shown in FIGS. 1, 14 and 15, can best be understood in light of the detailed construction of the beams 3, trim rails 7 and panels 5.

As shown in FIGS. 2-8, each sheet metal beam 3 is formed from a single sheet of steel and includes a spine part 1 1, a lamp housing part 13, and an attachment part 15. Spine part 11 and attachment part 15 are each bent outwardly 45 from the plane of the lamp housing part 13, to form angles of 135 with the lamp housing part 13. A continuous upper flange 17 on the beam 3 strengthens the beam. As shown at 19, the flange 17 is relieved at the junction of the spine part 11 and the lamp housing part 13, and at the junction between the attachment part 15 and the lamp housing part 13, and the flange is pleated somewhat to provide a strong and unbroken joint.

The spine part 11 includes a hook 21 at its distal end for engaging a hanger, for example a hanger of the type shown in the aforesaid Quin et al patent. A flange 23 on the lower, bearing, surface of the hook 21, and extending along the distal end of the broad face 25 of the spine 11 provides a bearing surface for the hook part and further stiffens the spine part 11. To compensate for the shift of the bearing surface 23 out of the plane of the broad face 25 of the spine, the upper portion 27 of the distal end of the spine is offset in a direction opposite the flange 17 by a distance equal to about half the width of the flange 23 (see FIG. 5). Extruded holes 29 and hole 30 in the broad face of the spine 11 reduces the weight of the beam and further strengthen the spine 11. Along the lower edge of the spine part 11 are a series of fingers 31, alternately offset to opposite sides of the broad face 25 of the spine 11. The fingers 31 act as spring clips for aligning and holding flanges on convergent edges of contiguous panels 5, as explained more fully hereinafter. At the proximal end of the spine part 11, six extruded holes 33 are provided for attaching the spine part 11 to the attachment part 15 of a contiguous beam 3, as explained more fully hereinafter.

The lamp housing part 13 of the beam 3 includes a broad face 35 having struck from it an inwardly and downwardly extending light baffle flap 37. The flap 37 also acts as a stop for a turned flange on the short base of the trapezoidal panel 5. At its right hand side, as viewed in FIG. 7, the flap 37 is provided with a small upwardly offset tab 38 for interlocking the corners of adjacent flaps 37. Along the lower edge of the slot formed by striking out the flap 37, the broad face 35 of the lamp housing part 13 is deformed outwardly to form a stiffener 39. A lower flange 53 on the lamp housing part 13 further stiffens this part of the beam. Standardized holes, lanced tabs, and knock-outs are provided in each lamp housing section 13, although not all are required for each possible variation of the module, and in any event not all are required in each section. Thus, knock-outs 41 are provided for wiring through each of the four beams 3, although generally those in only one beam will be used. Likewise, lanced slots 43 of two parallel opposed lamp housing parts 13 may be used for holding a closure element on the top plate 9. One depression 45 on each of two opposed lamp housing pieces 13 may hold a protruding end tab of a wiring saddle 46 extending across a lamp housing part 13 between the two aforementioned opposed parts. Tabs 47 struck inwardly and upwardly from the broad face 35 may support a bottom flange on the wiring saddle 46. Outwardly and downwardly extending tabs 49 (otherwise identical with the tabs 47) may be used to hold down a sound attenuation panel (shown in phantom lines in FIG. 14) when such panels are included in the module. Holes 51 at both ends of two opposed lamp housing parts 13 may receive pin parts slidably carried by a framed lighting panel, to support the panel in the open seat defined by the short bases of the panels 5 as described more fully hereinafter.

The attachment part 15 of the beam 3 includes a finger 55 at its lower edge which cooperates with the proximal finger 31 of the spine part 11 of a contiguous beam to form a spring clip for holding the upwardly turned flanges of contiguous panels 5. Punched holes 57 are adapted to receive the peripheral extruded part of the holes 33 of the spine 11 of a contiguous beam.

The framework is assembled simply by arranging the four beams 3 with the lamp housing parts 13 defining a square lamp housing and with the spline and attachment parts extending diagonally outward as shown in FIG. 1. ln this position the tab parts 38 of each baffle 37 overlap the adjacent baffle 37 and the extruded portions of the holes 33 extend through the holes 57. The extruded portions 33 are then deformed outwardly to form an eyelet by known pressing techniques, and the beams are thereby secured rigidly to each other to form a strong and stiff framework.

The trapezoidal panels 5 may be perforated panels, similar in construction to those disclosed in the aforesaid Quin et al patent and Halfaker application. Each panel has a long base, a short base and two convergent edges forming an angle of 45 with the long base. An integral upturned flange 59 is provided on each long base and a similar flange 61 is provided on each convergent edge of the panel 5. An upturned flange 63 at the inner (short) base of the trapezoidal panel 5 is taller than the other flanges on the panel 3 and includes an inturned lip 65. The flange 63 also includes holes (not shown) aligned with the holes 51 in the lamp housing part of the beam 3.

The panels 5 are attached to each other and to the beams 3 by arranging them so that their convergent edges are contiguous, their outside (long) bases define a square, and their inner (short) bases define an open seat, (giving the appearance of the modules shown in FIG. 1 of the aforesaid Quin et al patent). The framework may then be secured to the panels by placing the spines over the lines of contiguity of the panels 5, with lapped flanges 61 held in the spring clips formed by the fingers 31 and 55 and with the flanges 63 and lips 65 trapped by the broad faces 35 of the lamp housing parts 13 and by the light baffle flaps 37. The panels are then permanently secured to the spine parts by the use of standard fasteners or, preferably, by lancing a three sided cut through the fingers 31 and lapped flanges 61 and bending all three layers of material at right angles to the plane of the lapped flanges to form a locking tab.

The trim rails 7 are shown in FIGS. 9-13. Each trim rail includes an outwardly turned lip 67, a vertical riser part 69, an inwardly downwardly sloping shoulder 71 and an upper vertical flange 73. An upwardly offset tab 75 at one end of the lip 67 interlocks the lips of adjacent trim rails. An inwardly struck tab 77 engages the flange 59 on the long base of a panel 5. Holes 79 are also provided in the riser part 69 for conventional fasteners such as screws or rivets. The use of the tabs 77 minimizes the number of such conventional fasteners required. Openings 81 in the upper flange 73 are provided for mounting closure strips and the like above the channel defined by the trim rails 7 of adjacent modules in a completed ceiling. At each end of the vertical flange 73 an ear 83 is bent in the flange 73 for securement of the trim rail to an adjacent spine part. Each ear 83 includes an inwardly bent part 85 which, when the trim rails are mounted on the module, is perpendicular to the spine part and also includes an outwardly bent part 87 which is proportioned to be in face-to-face abutment with the spine when the trim rails are mounted on the module. An extruded hole 89 and a punched hole 89' are provided in the left and right hand ears 83 respectively. When the trim rails are mounted on the module, a single sheet metal screw through the hole 89 of one rail, a hole 91 in the spine part 11, and the hole 89 of an adjacent trim rail can secure both trim rails to that spine part and greatly increase the resistance of the spine part to deflection.

The closure plate 9 may have a peripheral flange 93 resting on the upper face of the flange 17 of the beams 3, and may have ventilator openings 94 in its upper face. It may be secured to the lamp housing by a pair lamp ballasts 95 and their wiring. Lamp sockets 97 mounted on the wireway cover 46 are provided for standard U-shaped fluorescent tubes 93. A diffuser 101 carried by an extruded frame 103 is mounted in the open seat defined by the flanges 63 on the panels 5 by means of four parallel spring-loaded pins 105 slidably mounted at the corners of the frame. The pins 1115 extend through opposed holes 51 in the lamp housing part 13 and the mating holes in the flanges 63.

lt will be seen that the preferred embodiment of ceiling module described is simple, extremely strong and relatively shallow, on the order of about 6 inches in depth. By way of illustration, the module may be about 59 inches across and the open seat may be about 28 inches across.

Although the foregoing embodiment is presently preferred, numerous variations will occur to those skilled in the art. For example, as shown in FIG. 16, the module may be made pyramidal by the use of a beam 203 which differs from the beam 3 in that its spine part slopes downwardly. Likewise, other light sources, such as a high intensity discharge lamp 210 having a ballast 212 may be carried on a cover plate 209 resting on the upper surface of the beams 203. Parabolic reflectors 214 may likewise be secured to the cover plate 209 and extend into a seat 216 defined by the inner edges of panels 205. Other variations in the invention, within the scope of the appended claims, will likewise be apparent to those skilled in the art.

Having thus described the invention, what is claimed and desired to be secured by Letters Patent is:

1. A ceiling module comprising a ceiling-defining area defined by four trapezoidal panels arranged in such a manner that each convergent edge of each said trapezoidal panel is contiguous a convergent edge of another of said trapezoidal panels, the long bases of said panels defining a rectangle, the short bases of said panels defining a rectangular open seat, the area defined by said rectangle being at least twice the area of said seat; framework means for supporting said panels, said framework means comprising a plurality of sheet metal beams, each of said beams having a broad vertical face with an upper edge and a lower edge, said ver tical faces of said beams being rigidly secured together face-to-face to form (a) the side walls of a rectangular lamp housing above said open seat and (b) four spines, each of said spines extending from a corner of said lamp housing to a corner of said rectangle along and above a line of contiguity between two of said panels; a lamp housing cover mounted on said upper edges of said broad vertical faces of said lamp housing side walls; and an electric light source mounted in said lamp housing.

2. The module of claim 1 wherein said framework comprises identical four beams, each of said beams comprising a lamp housing part, a spine part at one end of said lamp housing part and an attachment part at the other end of said lamp housing part, said attachment part being substantially shorter than said spine part.

3. The module of claim 2 wherein said spine part and said attachment part each extend at an angle of substantially to said lamp housing part, said spine part of each of said rails being secured face-to-face with said attachment part of an adjacent said beam.

4. The module of claim 3 wherein said spine part and said attachment part are secured by deforming the material of one of said spine part and said attachment part through an opening in the other of said spine part and attachment part.

5. The module of claim 4 wherein said spine part and said attachment part are secured to each other by means of an extruded hole in one of said spine part and said attachment part the peripheral material of said extruded hole extending through a clearance hole in the other of said spine part and attachment part and being deformed outwardly to hold said beams rigidly together.

6. The module of claim 3 wherein said panels lie in a common plane to define a flat ceiling area.

7. The module of claim 6 including mounting means at the outer end of said spines, above said panels, for mounting said module by its corners above the plane of said rectangle defined by said long bases of said panels.

8. The module of claim 7 wherein said mounting means comprises a hook integral with said spine, said hook including a turned lower edge, said spine including an offset for aligning the center of said turned edge with a line between said corner of said lamp housing and said corner of said rectangle.

9. The module of claim 1 wherein said open seat is defined by vertical flanges on the short bases of said panels and including a light controlling element mounted in said open seat.

10. The module of claim 9 wherein said light controlling element comprises a framed element removably secured in said seat by a plurality of horizontally extending pin parts slidably carried by the frame of said element, said pin parts extending into openings in said vertical walls of said open seat.

111. The ceiling module of claim 1 including socket means for supporting said light source, said socket means being mounted to said broad vertical face of at least one of said beams forming said lamp housing.

12. The ceiling module of claim 9 including light baffling means between said light source and said open seat, said light baffling means comprising a flap struck from said lamp housing part and extending inwardly into said lamp housing.

13. The module of claim 1 including a peripheral trim rail, said trim rail including four trim rail parts, each of said trim rail parts comprising turned ear parts at the ends of said trim rail part, said ear parts being secured to said spine in face-to-face relation.

14. The ceiling module of claim 1 including socket means for supporting said light source, said socket means being carried by said cover.

15. The ceiling module of claim 1 wherein said light source is contained completely between a plane defined by said upper edges and a plane defined by said lower edges of said lamp housing side walls.

16. A ceiling module comprising a light source and framework means for supporting said light source, said framework means comprising four identical sheet metal beams, each of said beams having a broad vertical face, each of said beams being bent to form (a) a central lamp housing part, (b) a spine part at one end of said lamp housing part, bent outwardly from the plane of said vertical face of said lamp housing part to form an angle of 135 with said lamp housing part, and (c) an attachment part at the other end of said lamp housing part, bent outwardly from the plane of said vertical face of said lamp housing part to form an angle of with said lamp housing part,

said beams being arranged to form a square lamp housing defined by broad vertical faces of said lamp housing parts and four diagonally outwardly extending spines formed by broad vertical faces of said spine parts, a broad vertical face of said attachment part of each said beam being secured face-to-face with a broad vertical face of said spine part of a contiguous said beam.

17. A ceiling module comprising:

a ceiling-defining area defined by four identical panels arranged in a common plane to define a flat ceiling area having a square perimeter and a central open square seat;

framework means for supporting said panels, said framework means consisting of four identical sheet metal beams, each of said beams having a broad vertical face, each of said beams comprising a central lamp housing part, a spine part at one end of said lamp housing part, and an attachment part at the other end of said lamp housing part, said beams being arranged to form a square lamp housing, formed by broad vertical faces of said lamp housing parts, above said open seat and four substantially vertical, outwardly extending spines, formed by broad vertical faces of said spine parts, extending above and along lines of contiguity between adjacent panels from a corner of said lamp housing to said periphery of said module,

said attachment part of each said beam being secured to an adjacent said beam at the juncture of said lamp housing part and said spine part of said adjacent beam; and

an electric light source mounted in said lamp hous- 18. The ceiling module of claim 17 wherein the area defined by said square perimeter is at least twice the area defined by said square seat.

19. A ceiling module comprising a ceiling-defining area comprising four trapezoidal panels arranged in such manner that each convergent edge of each said trapezoidal panel is contiguous a convergent edge of another of said trapezoidal panels, the long bases of the trapezoids defining a rectangle and the short bases of the trapezoids defining a rectangular open seat, a rectangular lamp housing above said open seat, said lamp housing having substantially vertical side walls, a light source mounted in said lamp housing, and a substantially vertical spine along each line of contiguity between adjacent panels and extending above said panels, characterized in that each one of said spines is formed integrally from a single structural member with one of said vertical side walls of said lamp housing.

20. A ceiling module comprising a ceiling-defining area defined by four trapezoidal panels arranged in such a manner that each convergent edge of each said trapezoidal panel is contiguous a convergent edge of another of said trapezoidal panels, the long bases of said panels defining a square, the short bases of said panels defining a square open seat, the area defined by said square being at least twice the area defined by said seat; a lamp housing above said open seat, said lamp housing being defined by four substantially vertical side walls and an upper wall; an electric light source guity between said panels, at least one of said outwardly bent parts being secured face-to-face with one of said spines, said upper wall comprising a cover mounted on said beams.

21. The module of claim 20 wherein each one of said spines is constituted by one of said outwardly bent parts of one of said beams. 

1. A ceiling module comprising a ceiling-defining area defined by four trapezoidal panels arranged in such a manner that each convergent edge of each said trapezoidal panel is contiguous a convergent edge of another of said trapezoidal panels, the long bases of said panels defining a rectangle, the short bases of said panels defining a rectangular open seat, the area defined by said rectangle being at least twice the area of said seat; framework means for supporting said panels, said framework means comprising a plurality of sheet metal beams, each of said beams having a broad vertical face with an upper edge and a lower edge, said vertical faces of said beams being rigidly secured together face-to-face to form (a) the side walls of a rectangular lamp housing above said open seat and (b) four spines, each of said spines extending from a corner of said lamp housing to a corner of said rectangle along and above a line of contiguity between two of said panels; a lamp housing cover mounted on said upper edges of said broad vertical faces of said lamp housing side walls; and an electric light source mounted in said lamp housing.
 2. The module of claim 1 wherein said framework comprises identical four beams, each of said beams comprising a lamp housing part, a spine part at one end of said lamp housing part and an attachment part at the other end of said lamp housing part, said attachment part being substantially shorter than said spine part.
 3. The module of claim 2 wherein said spine part and said attachment part each extend at an angle of substantially 135* to said lamp housing part, said spine part of each of said rails being secured face-to-face with said attachment part of an adjacent said beam.
 4. The module of claim 3 wherein said spine part and said attachment part are secured by deforming the material of one of said spine part and said attachment part through an opening in the other of said spine part and attachment part.
 5. The module of claim 4 wherein said spine part and said attachment part are secured to each other by means of an extruded hole in one of said spine part and said attachment part the peripheral material of said extruded hole extending through a clearance hole in the other of said spine part and attachment part and being deformed outwardly to hold said beams rigidly together.
 6. The module of claim 3 wherein said panels lie in a common plane to define a flat ceiling area.
 7. The module of claim 6 including mounting means at the outer end of said spines, above said panels, for mounting said module by its corners above the plane of said rectangle defined by said long bases of said panels.
 8. The module of claim 7 wherein said mounting means comprises a hook integral with said spine, said hook including a turned lower edge, said spine including an offset for aligning the center of said turned edge with a line between said corner of said lamp housing and said corner of said rectangle.
 9. The module of claim 1 wherein said open seat is defined by vertical flanges on the short bases of said panels and including a light controlling element mounted in said open seat.
 10. The module of claim 9 wherein said light controlling element comprises a framed element removably secured in said seat by a plurality of horizontally extending pin parts slidably carried by the frame of said element, said pin parts extending into openings in said vertical walls of said open seat.
 11. The ceiling module of claim 1 including socket means for supporting said light source, said socket means being mounted to said broad vertical face of at least one of said beams forming said lamp housing.
 12. The ceiling module of claim 9 including light baffling means between said light source and said open seat, said light baffling means comprising a flap struck from said lamp housing part and extending inwardly into said lamp housing.
 13. The module of claim 1 including a peripheral trim rail, said trim rail including four trim rail parts, each of said trim rail parts comprising turned ear parts at the ends of said trim rail part, said ear parts being secured to said spine in face-to-face relation.
 14. The ceiling module of claim 1 including socket means for supporting said light source, said socket means being carried by said cover.
 15. The ceiling module of claim 1 wherein said light source is contained completely between a plane defined by said upper edges and a plane defined by said lower edges of said lamp housing side walls.
 16. A ceiling module comprising a light source and framework means for supporting said light source, said framework means comprising four identical sheet metal beams, each of said beams having a broad vertical face, each of said beams being bent to form (a) a central lamp housing part, (b) a spine part at one end of said lamp housing part, bent outwardly from the plane of said vertical face of said lamp housing part to form an angle of 135* with said lamp housing part, and (c) an attachment part at the other end of said lamp housing part, bent outwardly from the plane of said vertical face of said lamp housing part to form an angle of 135* with said lamp housing part, said beams being arranged to form a square lamp housing defined by broad vertical faces of said lamp housing parts and four diagonally outwardly extending spines formed by broad vertical faces of said spine parts, a broad vertical face of said attachment part of each said beam being secured face-to-face with a broad vertical face of said spine part of a contiguous said beam.
 17. A ceiling module comprising: a ceiling-defining area defined by four identical panels arranged in a common plane to define a flat ceiling area having a square perimeter and a central open square seat; framework means for supporting said panels, said framework means consisting of four identical sheet metal beams, each of said beams having a broad vertical face, each of said beams comprising a central lamp housing part, a spine part at one end of said lamp housing part, and an attachment part at the other end of said lamp housing part, said beams being arranged to form a square lamp housing, formed by broad vertical faces of said lamp housing parts, above said open seat and four substantially vertical, outwardly extending spines, formed by broad vertical faces of said spine parts, extending above and along lines of contiguity between adjacent panels from a corner of said lamp housing to said periphery of said module, said attachment part of each said beam being secured to an adjacent said beam at the juncture of said lamp housing part and said spine part of said adjacent beam; and an electric light source mounted in said lamp housing.
 18. The ceiling module of claim 17 wherein the area defined by said square perimeter is at least twice the area defined by said square seat.
 19. A ceiling module comprising a ceiling-defining area comprising four trapezoidal panels arranged in such manner that each convergent edge of each said trapezoidal panel is contiguous a convergent edge of another of said trapezoidal panels, thE long bases of the trapezoids defining a rectangle and the short bases of the trapezoids defining a rectangular open seat, a rectangular lamp housing above said open seat, said lamp housing having substantially vertical side walls, a light source mounted in said lamp housing, and a substantially vertical spine along each line of contiguity between adjacent panels and extending above said panels, characterized in that each one of said spines is formed integrally from a single structural member with one of said vertical side walls of said lamp housing.
 20. A ceiling module comprising a ceiling-defining area defined by four trapezoidal panels arranged in such a manner that each convergent edge of each said trapezoidal panel is contiguous a convergent edge of another of said trapezoidal panels, the long bases of said panels defining a square, the short bases of said panels defining a square open seat, the area defined by said square being at least twice the area defined by said seat; a lamp housing above said open seat, said lamp housing being defined by four substantially vertical side walls and an upper wall; an electric light source mounted in said lamp housing; and framework means for supporting said panels, said framework means comprising four substantially vertical spines extending along and above lines of contiguity between adjacent panels, said four side walls of said lamp housing being four identical sheet metal beams, each of said beams having at each of its ends an integral part bent outwardly from the plane of said side wall and extending outwardly from said lamp housing along a line of contiguity between said panels, at least one of said outwardly bent parts being secured face-to-face with one of said spines, said upper wall comprising a cover mounted on said beams.
 21. The module of claim 20 wherein each one of said spines is constituted by one of said outwardly bent parts of one of said beams. 